1. Field of the Invention
The present invention relates to developing apparatus preferably used in image forming apparatuses such as electrophotograph copying machines and electrophotograph printers, and an assembling method of the developing apparatus. The developing apparatus can be disposed in a cartridge which is detachably attachable to a main body of an image forming apparatus.
2. Related Background Art
It has conventionally been proposed an image forming apparatus for forming a multicolor image by electrophotography which has a configuration for a method capable of forming a multicolor image by disposing a plurality of developing cartridges containing developers (toners) of different colors on a rotating selection mechanism (developing rotary) for a photosensitive drum which is an electrophotographic photosensitive body, arranging a developing cartridge containing a developer of a predetermined color in opposition to the above described photosensitive drum, developing and visualizing a latent image into a developed image, transferring the developed image to a recording medium, and repeating developing and transferring operations for each color. There has been proposed also a method which configures the above described developing cartridge as a cartridge which is detachably attachable to a main body of an image forming apparatus so as to lessen a maintenance work of a user.
Such a developing cartridge is composed by combining a developing roller which is a developer carrying body, a developing blade which is a developer regulating member for regulating a thickness of a toner to be coated over the above described developing roller, a developing frame (developing member supporting frame) which supports a developing member such as a coating roller for coating the developing roller with the toner and a toner frame which contains the toner. This kind of developing cartridge is generally configured to enhance straightness and flatness of a support plate of the above described developing blade so that the developing blade is kept in uniform contact with the developing roller.
Furthermore, it is customary to fix both ends of the developing blade with machine screws so that the developing blade will not move relative to a developer container.
There have been proposed a process cartridge in which the above described developing cartridge is built as developing means and an image forming apparatus which comprises the process cartridge.
Conventionally, it is technically difficult to uniformalize a pressure of a developing blade applied to a developing roller in a longitudinal direction so as to uniformalize a layer thickness of a developer on the developing roller and it is desired to improve a technique for uniformalizing a pressure.
Though it is known to interpose an elastic blade between a support plate and a clamp plate, it is desired to omit the clamp plate to reduce a number of parts.
An object of the present invention relates to a developing apparatus and an assembling method for this apparatus which are capable of uniformalizing a thickness of a developer carried on a developer carrying body, thereby preventing an uneven image density from being produced.
Another object of the present invention relates to a developing apparatus and an assembling method for this apparatus which uniformalize a pressure of a developing blade against a developer carrying body in a longitudinal direction.
Still another object of the present invention relates to a developing apparatus which is capable of reducing the number of parts and an assembling method for this apparatus.